Additionally, NK4 reduced the phosphorylation level of NF-κB p65 and upregulated the expression of sirt1, but did not change the levels of p38 and p-p38 in RA-FLS and MH7A cells.
Additionally, pseurotin A ameliorated the protein expressions of osteoprotegerin, nuclear factor of activated T-cells, nuclear factor-kappa beta (NF-κB), IκBα, extracellular signal regulated kinase, and P38 as well as histopathological changes in the synovial tissue of CIA-induced RA rats.
Furthermore, ROS generation, p47phox-Ser345 phosphorylation, and ERK1/2 and p38 MAPK phosphorylation were increased in synovial neutrophils from rheumatoid arthritis (RA) patients, and TAT-Ser345 peptide inhibited ROS production by these primed neutrophils.
IL-18 induced phosphorylation of JNK, PKCdelta, p38 MAPK, and activating transcription factor 2 (ATF-2) in RA ST fibroblasts in a time-dependent manner, with JNK-2 being upstream of PKCdelta, ATF-2, and NFkappaB.
Inhibitors of p38 MAPK or JNK activation provide protection against inflammation and fibrosis in animal models of kidney disease; however, clinical trials of p38 MAPK and JNK inhibitors in other diseases (rheumatoid arthritis and pulmonary fibrosis) have been disappointing.
Therefore, we sought to determine if the tumor suppressor gene product retinoblastoma (Rb), a negative regulator of cell cycle activity, inhibits IL-6, MMP-1, and p38 in RA synovial fibroblasts.
Thus, our data show that developing specific inhibitors of the alpha-isoenzyme of p38 would be beneficial for the treatment of inflammation-induced bone destruction as observed in rheumatoid arthritis.
Together, these findings illustrate how stimulatory context can alter dominance in pathway cross-talk even for a fixed network topology, thereby providing a rationale for why p38 inhibitors deliver limited benefits in RA and demonstrating the need for careful consideration of p38-targeted drugs in inflammation-related disorders.
Treatment with PIP-18 blocked IL-1beta-induced p38 MAPK phosphorylation and resulted in attenuation of sPLA2-IIA and MMP mRNA transcription in RA SF cells.
TTP expression was significantly higher in RA than non-inflamed synovium, detected in macrophages, vascular endothelial cells and some fibroblasts and co-localised with MAPK p38 activation.
We focused on prominent p38 mitogen-activated protein (MAP) kinase p38α which is a prime regulator of tumor necrosis factor-α (TNF-α), a key mediator of rheumatoid arthritis.